The greatest playground game ever created by man. All you need to play is a decent-sized group of people, a tennis ball, and a (preferably brick) wall without windows. Some people play with a racquet ball for a tougher challenge.

The object of this game is to be the last man surviving. Players throw the tennis ball against the wall in hopes that it'll another player will try and get the ball and fail to.

The tennis ball bounces across the ground and a player will get it and throw it back against the wall. If a player gets hit with the ball they have to go a haul ass to the wall and touch it with any part of the body to be safe. If another player gets the ball, throws it, and hits the wall before the runner touches the wall, the runner is "out." (Close calls and ties always go to the runner.) Once someone gets out three times, they are done for the remainder of the game. Another way a player can get an out is if they throw the ball and someone else catches it before it hits the ground.

Double-Touch Out: A variation of the game, where if a player touches the ball, the ball touches the ground, and the player touches the ball, they receive and out. A finally way to get out is if you take more than a throwing step while in possession of the ball.

Spread-Eagle: Once a player gets their three outs, the get up against the wall and into the spread eagle position. Players who aren't out get the option to peg the player for free, but from a distance. They better pray to God they don't get hit in the Big Jim and the Twins or their face. But once it's all said and done, and the player has been pegged, they are free to join back in.

Drumline: A third variation, where after a player gets three outs, they go to the end of the wall. The player has to run back and forth across the wall a given number of times without getting hit with the ball to get back in. For example: A player runs back and forth across the wall 10 times without being pelted or touched by the ball in anyway and then they get a new set of outs.

Pegs: A somewhat outlawed version to the game. People can throw the ball at other players so that the player has to run to the wall. However, the person who hits that player has to run too.

Wallball is my favorite game to play on the playground or blacktop during recess.

Game where a group of friends throws a ball on a wall. If you accidentally drop the bal trying to catch it, you have to run to the wall and tag it as fast as you can before someone else throws the ball. If the ball hits the wall before you tag it you are out of the game. If you get 3 outs you have to stand up against the wall and have the person who gave you the last out stand as far as possible and try to throw the ball at you.

The greatest thing to hit Suburban America since the back yard.
A (dare I say it) sport in which people throw a ball at a wall, hoping an opponet drops it so they can throw the ball to get an out. At three outs, they go to the wall and await a peg. Be sure to cover up the coin purse if you wanna have kids when it's all said and done.
For the most part, the rules are very flexible, so you can make up hundreds of different versions, like Spread the Eagle, Drumline Wallball, or even Fireball (where you soak a tennis ball w/ gasoline, light it, and play with gloves)

If the guys at ESPN put Scrabble and the Spelling Bee on the air, I wanna see Wallball!

An awesome game with many variations that originated in Encinitas. Hit a red ball about the size of a tether ball against a wall, preferably brick or stone. The ball has to bounce before hitting (can only bounce ONCE) and has to bounce either not at all or one time before you hit or catch it. Only two people play at once. Once someone gets out, the next person in line joins in. Certain things can be called, and in some games, moves can be done such as rainbows (going under the ball; counts for your turn). Failing to complete turn or complete it correctly results in you being out.

Common Variations:
ELIMINATION - Everyone plays at once!
BACK OF THE BUS - Elimination where getting out makes you go to the position of last in order.
BUTTS UP - The ball can bounce an unlimited amount of times before one catches it. Can't bounce before hitting the wall — if it does, someone has to grab it and throw it against the wall. If the ball reaches the wall before you do, you're out. Unlimited players, and no turns. And no, no one knows why the hell it's called Butt's Up.
BACK OF THE BUS - Similar to elimination, but where getting out
EVERYTHING - A bunch of lame moves can be made, like Slicies (sticking your arm under the ball instead of hitting it) and Legbows (same thing with your leg). Can be played Elimination-Style or One-on-One.

The last game of wallball we played, some idiot legbowed it and tried to claim he didn't know there were no damn legbows OR slicies.